JP2019151784A - Azo compound, ink composition, recording method and colored material - Google Patents

Abstract

To provide a compound that has high storage stability, and when recorded on inkjet exclusive paper, has high print density and excellent color rendering property, has high-grade black hue with low chroma saturation and is excellent in (ozone) gas resistance in particular.SOLUTION: An azo compound represented by formula (1), its tautomer or a salt thereof is provided. [Rrepresents an alkyl group or an alkyl group substituted with a carboxyl group; Rrepresents a cyano group; Rand Reach independently represent H, an alkoxyl group or a sulfo group; Rrepresents an alkylthio group substituted with at least one kind of group selected from HO, a sulfo group and a carboxyl group; Rrepresents an alkylthio group substituted with at least one kind of group selected from HO, a sulfo group and a carboxyl group; Rrepresents an alkylthio group substituted with at least one kind of group selected from HO, a sulfo group and a carboxyl group; Rto Rrepresent an alkylcarbonylamino group; and Rto Reach independently represent H, a sulfo group, a carboxyl group, HO or a nitro group.]SELECTED DRAWING: None

Description

  The present invention relates to a novel azo compound or a tautomer thereof, or a salt thereof, an ink composition containing them, and a colored product colored by them.

A recording method using an ink jet printer, that is, an ink jet recording method is one of representative methods among various color recording methods. The ink jet recording method performs recording by generating droplets of ink and attaching them to various recording materials (paper, film, fabric, etc.). This method is quiet because it does not generate sound because the recording head and the recording material are not in direct contact. Moreover, since it has the feature that it is easy to reduce the size and increase the speed, it has been rapidly spreading in recent years and is expected to grow greatly in the future.
Conventionally, water-based inks in which water-soluble pigments are dissolved in an aqueous medium have been used as fountain pens, felt-tip pens, and inks for ink jet recording. In general, a water-soluble organic solvent is added to these water-based inks in order to prevent clogging of the ink at the pen tip or the ink discharge nozzle. These inks provide a recorded image with sufficient density, do not cause clogging of the pen tip and nozzles, have good drying properties on recording materials, have little bleeding, and have storage stability. It is required to be excellent. In addition, the water-soluble dye used is required to have particularly high solubility in water and high solubility in a water-soluble organic solvent added to the ink. Further, the formed image is required to have image fastness such as water resistance, light resistance, gas resistance and moisture resistance.

  Among these, the gas resistance refers to the resistance to a phenomenon in which ozone gas having an oxidizing action existing in the air acts on the dye on the recording material or in the recording material to cause the recorded image to discolor. It is. In addition to ozone gas, examples of the oxidizing gas having this kind of action include NOx and SOx. However, among these oxidizing gases, ozone gas is regarded as a main causative substance that promotes the discoloration phenomenon of ink jet recorded images, and particularly, ozone gas resistance is regarded as important. An ink receiving layer is provided on the surface of the exclusive inkjet paper that provides photographic image quality in order to speed up drying of the ink and to reduce bleeding at high image quality. In many cases, the ink receiving layer is made of a material such as a porous white inorganic material. On such a recording paper, the discoloration due to ozone gas or the like is noticeable. Since this discoloration phenomenon due to the oxidizing gas is characteristic of an ink jet recording image, improvement of gas resistance, particularly ozone gas resistance, is one of the most important issues in ink jet recording.

  In addition, the bronzing phenomenon may be a problem. The bronzing phenomenon is a phenomenon in which the dye becomes flickering on the metal piece on the surface of the non-recording material due to the association of the dye or the poor absorption of the ink. When this phenomenon occurs, the gloss, print quality, and print density are all inferior. Especially when a metal phthalocyanine dye is used as a pigment, it often appears as a “red float phenomenon” in the portion printed at a high density, and the balance of the entire image becomes non-uniform and the quality is deteriorated. A pigment that does not cause a phenomenon is desired. In recent years, glossy paper is often used as a recording medium having a texture close to a photographic tone. However, when the bronzing phenomenon occurs, the glossiness on the surface of the recorded material varies, and the texture of the image is significantly impaired. From this viewpoint, there is a strong demand for a dye that does not cause a bronzing phenomenon. In addition, in this specification, the pigment | dye which does not produce this bronzing phenomenon is described as a pigment | dye which is excellent in bronzing property.

  In the future, in order to expand the field of use of ink jet recording, further improvement in light resistance, gas resistance, moisture resistance, water resistance, bronzing resistance and the like is strongly demanded for ink jet recorded images. In addition to this, black images are required to have excellent color rendering properties. A phenomenon in which the hue appears to change depending on the type of the light source is referred to as color rendering, but generally this phenomenon is likely to occur in black dyed matter or recorded matter. In the field of dyeing processing, it is common to use a compound having absorption at a long wavelength as a method for improving color rendering properties. For example, Patent Document 6 discloses these methods.

  Various hue inks are prepared from various pigments, of which black ink is an important ink used for both monocolor and full color images. Many pigments for these black inks have been proposed to date, but they have not yet provided a pigment that sufficiently satisfies the demands of the market. Many of the proposed dyes are azo dyes, of which C.I. I. Disazo dyes such as Food Black 2 have problems such as poor water resistance and moisture resistance, insufficient light resistance and gas resistance, and high color rendering. A polyazo dye having an extended conjugated system generally has problems such as low water solubility, easily causing a bronzing phenomenon in which a recorded image has a partially metallic luster, and insufficient light resistance and gas resistance. Similarly, many azo metal-containing dyes that have been proposed have good light resistance, but they contain metal ions, which are undesirable for biological safety and environmental problems, and have extremely low gas resistance. There are problems such as.

  As a black compound (black pigment) for ink jet recording improved with respect to gas resistance, which has become the most important issue in recent years, for example, the compounds described in Patent Document 1 can be mentioned. Although the gas resistance of these compounds has been improved, they do not fully meet market demands. Further, azo compounds having a benzimidazolopyridone skeleton, which is one of the characteristics of the black pigment of the present invention, are disclosed in Patent Documents 3 to 5 and the like. Patent Documents 3 and 4 disclose that a trisazo compound and a water-soluble black compound are used for inkjet recording. Patent Documents 5 and 8 disclose that a tetrakisazo compound and a water-soluble black compound are used for inkjet recording, but a black pigment having excellent hue and good ozone gas resistance is strong. It has been demanded.

International Publication No. 2005/054374 International Publication No. 2004/050768 International Publication No. 2007/077931 International Publication No. 2009/069279 JP 2008-169374 A Japanese Patent Laid-Open No. 01-284562 JP 2004-75719 A International Publication 2012/081640 International Publication No. 2014/132926

  The present invention is particularly excellent in ozone gas resistance, excellent in light resistance and moisture resistance, very high in print density, excellent in bronzing resistance, color rendering, and low in saturation when recorded on inkjet paper. Another object of the present invention is to provide a pigment having a high-quality black hue, and an ink composition containing the pigment, particularly a black ink composition for inkjet recording.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific azo compound can solve the above problems, and have completed the present invention.

That is, the present invention relates to the following 1) to 10).
1)
An azo compound represented by the following formula (1), a tautomer thereof, or a salt thereof.

[In Formula (1),
R ₁ represents a (C1-C4) alkyl group or a (C1-C4) alkyl group substituted with a carboxy group,
R ₂ represents a cyano group,
R ₃ and R ₄ each independently represents a hydrogen atom, a (C1-C4) alkoxyl group, or a sulfo group,
R ₅ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ₆ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ₇ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ₈ represents a (C1 to C4) alkylcarbonylamino group,
R ₉ is a (C1-C4) alkylcarbonylamino group,
R ₁₀ represents a (C1-C4) alkylcarbonylamino group,
R _{11 to} R ₁₃ are each independently a hydrogen atom, a sulfo group, a carboxy group, a hydroxy group, or a nitro group. In addition, when there is no ring represented by a broken line, a benzene ring, when there is a ring represented by a broken line, a naphthalene ring, and when it is a naphthalene ring, the substituents R _{11 to} R ₁₃ are each a naphthalene ring. Can be substituted at any position. ]
2)
In the above formula (1),
R ₁ represents a (C1-C4) alkyl group or a (C1-C4) alkyl group substituted with a carboxy group,
R ₂ represents a cyano group,
R ₃ and R ₄ each independently represents a hydrogen atom, a (C1-C4) alkoxyl group, or a sulfo group,
R ₅ represents a sulfo (C1-C4) alkylthio group,
R ₆ represents a sulfo (C1-C4) alkylthio group, R ₇ represents a sulfo (C1-C4) alkylthio group,
R ₈ represents a (C1 to C4) alkylcarbonylamino group,
R ₉ is a (C1-C4) alkylcarbonylamino group,
R ₁₀ represents a (C1-C4) alkylcarbonylamino group,
The azo compound according to claim 1, or a tautomer thereof, or a salt thereof, wherein R _{11 to} R ₁₃ are each independently a hydrogen atom, a sulfo group, a carboxy group, a hydroxy group, or a nitro group.
3)
In the above formula (1),
R ₁ is a methyl group,
R ₂ is a cyano group,
R ₃ is a methoxy group or a hydrogen atom,
R ₄ is a sulfo group,
R ₅ is a sulfo (C1-C4) alkylthio group,
R ₆ is a sulfo (C1-C4) alkylthio group,
R ₇ is a sulfo (C1-C4) alkylthio group,
R ₈ is an acetylamino group,
R ₉ is an acetylamino group,
R ₁₀ is an acetylamino group,
R _{11 to} R ₁₃ are each independently a hydrogen atom, a sulfo group, a carboxy group, a hydroxy group or a nitro group, the azo compound according to 1) or 2) or a tautomer thereof, or a salt thereof .
4)
A water-based ink composition comprising at least one kind of the azo compound according to any one of 1) to 3) or a tautomer thereof, or a salt thereof as a dye.
5)
The water-based ink composition according to 4), further comprising a water-soluble organic solvent.
6)
An ink jet recording method in which recording is performed on a recording material by using the water-based ink composition according to 4) or 5) as an ink and ejecting ink droplets of the ink according to a recording signal.
7)
The inkjet recording method according to 6), wherein the recording material is an information transmission sheet.
8)
7. The ink jet recording method according to 7), wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance.
9)
An ink jet printer loaded with a container containing the water-based ink composition described in 4) or 5).
10)
a) The azo compound according to any one of 1) to 3) or a tautomer thereof, or a salt thereof,
b) The water-based ink composition according to 4) or 5), or
c) A colored body colored by any one of the three methods described in 6).

  The azo compound or a tautomer thereof, or a salt thereof, and an ink composition containing the azo compound have high storage stability, are suitably used as an ink for ink jet recording, and further recorded on ink jet dedicated paper. The printing density is very high, the color rendering property is excellent, the saturation is low, it has a high-quality black hue, and particularly the (ozone) gas resistance is excellent. Therefore, the ink composition containing the azo compound of the present invention or a tautomer thereof, or a salt thereof is extremely useful as a black ink for inkjet recording.

Hereinafter, the present invention will be described in detail.
For the sake of convenience, in the present specification, the term “azo compound”, including all of “azo compounds or tautomers thereof, or salts thereof”, will be simply described below. Here, examples of the tautomer include structures represented by the following formulas (3) and (4). In formulas (3) and (4), R _{1 to} R ₁₃ have the same meaning as in formula (1) above.

In the above formula (1), R ₁ represents a (C1 -C4) alkyl group, or substituted by a carboxy group (C1 -C4) alkyl group.

Examples of the (C1 to C4) alkyl group in R ₁ include a linear or branched alkyl group, and a linear alkyl group is preferable. Specific examples of the (C1-C4) alkyl group include, for example, a straight chain alkyl group such as a methyl group, an ethyl group, an n-propyl group, and an n-butyl group, an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. And a branched alkyl group such as a group. Preferable specific examples include a methyl group and an n-propyl group, and a methyl group is more preferable.

Examples of the (C1 to C4) alkyl group substituted with a carboxy group in R ₁ include those in which a carboxy group is substituted on any carbon atom of the (C1 to C4) alkyl group. The substitution position of the carboxy group is not particularly limited, but it is preferably substituted at the end of the alkyl group, and the number of substitution of the carboxy group is 1 or 2, preferably 1. Specific examples include a carboxymethyl group and a 2-carboxyethyl group. A preferred specific example is a carboxymethyl group.

The R ₁ is preferably a (C ₁ -C 4) alkyl group or a (C ₁ -C 4) alkyl group substituted with a carboxy group, more preferably a (C ₁ -C 4) alkyl group. More preferred is a methyl group or n-propyl group, and particularly preferred is a methyl group.

In the formula (1), R ₂ represents a cyano group.

In said formula (1), R < ₃ > and R < ₄ > represents a hydrogen atom, a (C1-C4) alkoxyl group, or a sulfo group each independently.

Examples of the (C1 to C4) alkoxyl group in R ₃ and R ₄ include a linear or branched alkoxyl group, and a linear alkoxyl group is preferable. Specific examples include linear alkoxyl groups such as methoxy group, ethoxy group, n-propoxy group and n-butoxy group, branched alkoxyl groups such as isopropoxy group, isobutoxy group, sec-butoxy group and tert-butoxy group, Etc. In these, a methoxy group is more preferable.

As R ₃ and R ₄ , either one is a methoxy group and the other is a combination of a sulfo group, or one of them is a hydrogen atom and the other is a combination of a sulfo group, more preferably one of them. Is a methoxy group and the other is a combination of sulfo groups.

The substitution position of R ₃ and R ₄ is not particularly limited. However, when one of them is a hydrogen atom and the other is a sulfo group, the sulfo group has four carbon atoms that do not constitute the imidazole ring of the benzimidazolopyridone ring. It is preferable to substitute any two of these.

The compound represented by the above formula (1) may be used as a mixture containing at least two kinds of positional isomers at the substitution positions of R ₃ and R ₄ from the viewpoint of ease of synthesis and low cost.

As a preferable combination of R _{1 to} R ₄ in the above formula (1), R ₁ is a (C1 to C4) alkyl group (preferably a methyl group or an n-propyl group, more preferably a methyl group), and R ₂ is a cyano group. A combination of a group, R ₃ is a hydrogen atom, or a methoxy group (preferably a methoxy group), and R ₄ is a sulfo group.

In said formula (1), R < ₅ > -R < ₇ > represents the (C1-C4) alkylthio group substituted by the at least 1 sort (s) of group selected from the group which consists of a hydroxy group, a sulfo group, and a carboxy group each independently.

As the substituent in R _{5 to} R _7, as the (C1 to C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group, (C1 to C4) ) Any carbon atom in the alkylthio group includes those having these substituents. The number of the substituents is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited, but is preferably substituted with a carbon atom other than the carbon atom to which the sulfur atom in the alkylthio group is bonded.
Specific examples thereof include 2-hydroxyethylthio group, 2-hydroxypropylthio group, 3-hydroxypropylthio group, 2-sulfoethylthio group, 3-sulfopropylthio group, 2-carboxyethylthio group, 3 -Carboxypropylthio group, 4-carboxybutylthio group, etc. are mentioned.

Among the above, preferable R _{5 to} R ₇ include a sulfo (C1 to C4) alkylthio group or a carboxy (C1 to C4) alkylthio group, more preferably a sulfo (C1 to C4) alkylthio group, and 3-sulfopropyl. A thio group is particularly preferred.

In said formula (1), R < ₈ > -R < ₁₀ > represents a (C1-C4) alkyl carbonylamino group each independently.

The (C1 -C4) alkylcarbonylamino group in R ₈ to R _10, the alkyl moiety is a straight chain or branched chain and the like, a straight chain is preferred. Specific examples thereof include, for example, straight-chain groups such as acetylamino group (methylcarbonylamino group), propionylamino group (ethylcarbonylamino group), n-propylcarbonylamino group, n-butylcarbonylamino group, isopropylcarbonylamino Group, branched chain groups such as isobutylcarbonylamino group, sec-butylcarbonylamino group, pivaloylamino group (tert-butylcarbonylamino group) and the like, and acetylamino group is more preferable.

R _{11 to} R ₁₃ are each independently a hydrogen atom, a carboxy group, a sulfo group, a hydroxy group, an acetylamino group, a halogen atom, a cyano group, a nitro group, a sulfamoyl group, a (C1 to C4) alkyl group, (C1 -C4) (C1-C4) alkoxyl group substituted with at least one group selected from the group consisting of alkoxyl group, hydroxy group, (C1-C4) alkoxyl group, sulfo group and carboxy group, (C1-C4) ) Represents an alkylsulfonyl group, or a (C1-C4) alkylsulfonyl group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group, and any of R _{11 to} R ₁₃ Or at least one is a sulfo group.

The (C1-C4) alkoxy group substituted with at least one group selected from the group consisting of a hydroxy group, a (C1-C4) alkoxyl group, a sulfo group, and a carboxy group in R _{11 to} R ₁₃ above, in the R ₈ to R _10, hydroxy group, a (C1 -C4) alkoxyl group, a sulfo group, and substituted by at least one group selected from the group consisting of carboxy (C1 -C4) alkoxy group, The same thing is mentioned including a preferable thing. The (C1 -C4) alkylsulfonyl group in R ₁₁ to R _13, include an alkylsulfonyl group having a linear or branched chain, preferably straight-chain alkylsulfonyl groups. Specific examples include linear alkylsulfonyl groups such as methylsulfonyl, ethylsulfonyl, n-propylsulfonyl and n-butylsulfonyl, branched alkylsulfonyl groups such as isopropylsulfonyl and isobutylsulfonyl, and the like. Of the above, methylsulfonyl, ethylsulfonyl, and isopropylsulfonyl are preferable, and methylsulfonyl is particularly preferable. As the substituent in R ₁₁ to R ₁₃ , the (C1 to C4) alkylsulfonyl group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group includes the above (C1 to C1). C4) The above-mentioned groups are substituted on any carbon atom in the alkylsulfonyl group, and the number of the substituents is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited. Specific examples include hydroxy-substituted alkylsulfonyl groups such as hydroxyethylsulfonyl and 2-hydroxypropylsulfonyl, sulfo-substituted alkylsulfonyl groups such as 2-sulfoethylsulfonyl and 3-sulfopropylsulfonyl, 2-carboxyethylsulfonyl and 3-carboxy. And carboxy-substituted alkylsulfonyl groups such as propylsulfonyl.

Among the above, preferable R ₁₁ includes a hydrogen atom, a carboxy group, a sulfo group, a nitro group, a chlorine atom, a methyl group, a methoxy group, and a (C1 to C4) alkylsulfonyl group. A carboxy group, a sulfo group, a nitro group, a chlorine atom, a (C1-C4) alkylsulfonyl group, or a methyl group and a methoxy group are more preferable, and a hydrogen atom and a sulfo group are particularly preferable.

Among the above, preferable R ₁₂ is a hydrogen atom, a carboxy group, a sulfo group, a nitro group, a chlorine atom, a methyl group, a methoxy group, a sulfamoyl group, a (C1 to C4) alkylsulfonyl group, or a carboxy (C1 to C4) alkyl. A sulfonyl group, a sulfo (C1-C4) alkylsulfonyl group, a hydrogen atom or an electron-withdrawing substituent such as a carboxy group, a sulfo group, a nitro group, a chlorine atom, a sulfamoyl group, a (C1-C4) alkylsulfonyl group, A carboxy (C1 to C4) alkylsulfonyl group, a sulfo (C1 to C4) alkylsulfonyl group, or a methyl group or a methoxy group is more preferable, and a sulfo group, a nitro group, a methyl group, a methoxy group, a sulfamoyl group, a sulfopropylsulfonyl group, A carboxyethylsulfonyl group is more preferred, and a sulfo group is particularly preferred. Preferred.

Among these, preferable R ₁₃ includes a hydrogen atom, a carboxy group, a sulfo group, a methoxy group, a nitro group, a chlorine atom, and a (C1 to C4) alkylsulfonyl group, and is a hydrogen atom or an electron-withdrawing substituent. A carboxy group, a sulfo group, a nitro group, a chlorine atom, a (C1-C4) alkylsulfonyl group, or a methoxy group is more preferable, and a sulfo group is particularly preferable.

Specific examples of preferable combinations of R _{1 to} R ₁₃ in the above formula (1) include the following combinations (i) to (v). (Ii) or (iii) is more preferable, and (iv) or (v) is more preferable.

(I)
R ₁ is a methyl group,
R ₂ is a cyano group,
R ₃ is a hydrogen atom or a methoxy group,
R ₄ is a sulfo group,
(C1-C4) alkylthio group substituted with a sulfo group or a carboxy group, R ₅ ;
(C1-C4) alkylthio group substituted with a sulfo group or a carboxy group, R ₆ ;
(C1-C4) alkylthio group substituted with a sulfo group or a carboxy group, R ₇ ;
R ₈ is a (C1-C4) alkylcarbonylamino group,
R ₉ is a (C1-C4) alkylcarbonylamino group,
R ₁₀ is a (C1-C4) alkylcarbonylamino group,
R ₁₁ is a hydrogen atom, a sulfo group or a nitro group,
R ₁₂ is a hydrogen atom, a sulfo group or a nitro group,
R ₁₃ is a hydrogen atom, a sulfo group or a nitro group,
Combination.

(Ii)
R ₁ is a methyl group,
R ₂ is a cyano group,
R ₃ is a hydrogen atom or a methoxy group,
R ₄ is a sulfo group,
R ₅ is a sulfo (C1-C4) alkylthio group,
R ₆ is a sulfo (C1-C4) alkylthio group,
R ₇ is a sulfo (C1-C4) alkylthio group,
R ₈ is a (C1-C4) alkylcarbonylamino group,
R ₉ is a (C1-C4) alkylcarbonylamino group,
R ₁₀ is a (C1-C4) alkylcarbonylamino group,
R ₁₁ is a sulfo group,
R ₁₂ is a sulfo group,
R ₁₃ is a hydrogen atom, a sulfo group or a nitro group,
Combination.

(Iii)
R ₁ is a methyl group,
R ₂ is a cyano group,
R ₃ is a hydrogen atom or a methoxy group,
R ₄ is a sulfo group,
R ₅ is a sulfo (C1-C4) alkylthio group,
R ₆ is a sulfo (C1-C4) alkylthio group,
R ₇ is a sulfo (C1-C4) alkylthio group,
R ₈ is a (C1-C3) alkylcarbonylamino group,
R ₉ is a (C1-C3) alkylcarbonylamino group,
R ₁₀ is a (C1-C3) alkylcarbonylamino group,
R ₁₁ is a sulfo group,
R ₁₂ is a sulfo group,
R ₁₃ is a hydrogen atom or a sulfo group,
Combination.

(Iv)
R ₁ is a methyl group,
R ₂ is a cyano group,
R ₃ is a hydrogen atom or a methoxy group,
R ₄ is a sulfo group,
R ₅ is a sulfo (C1-C4) alkylthio group,
R ₆ is a sulfo (C1-C4) alkylthio group,
R ₇ is a sulfo (C1-C4) alkylthio group,
R ₈ is an acetylamino group,
R ₉ is an acetylamino group,
R ₁₀ is an acetylamino group,
R ₁₁ is a sulfo group,
R ₁₂ is a sulfo group,
R ₁₃ is a hydrogen atom or a sulfo group,
Combination.

(V)
R ₁ is a methyl group,
R ₂ is a cyano group,
R ₃ is a hydrogen atom or a methoxy group,
R ₄ is a sulfo group,
R ₅ is a sulfopropylthio group,
R ₆ is a sulfopropylthio group,
R ₇ is a sulfopropylthio group,
R ₈ is an acetylamino group,
R ₉ is an acetylamino group,
R ₁₀ is an acetylamino group,
R ₁₁ is a sulfo group,
R ₁₂ is a sulfo group,
R ₁₃ is a hydrogen atom,
Combination.

  The compound which combined the preferable thing described about various substituents in the said Formula (1), those combinations, those substitution positions, etc. is more preferable, and what combined the more preferable things is still more preferable. The same applies to preferable combinations, preferable combinations, and more preferable combinations.

The tetrakisazo compound represented by the above formula (1) can be synthesized, for example, by the following method. In addition, the structural formula of the compound in each process shall be represented with the form of a free acid. In the following formulas (5) to (12), R _{1 to} R ₁₃ are the same as those in the above formula (1).
A compound represented by the following formula (5) is diazotized by a conventional method, and the obtained diazo compound and a compound represented by the following formula (6) are subjected to a coupling reaction by a conventional method, and represented by the following formula (7). To obtain the compound.

  The obtained compound represented by the above formula (7) is diazotized by a conventional method, and then the obtained diazo compound and a compound represented by the following formula (8) are subjected to a coupling reaction by a conventional method, The compound represented by (9) is obtained.

  The obtained compound represented by the above formula (9) is diazotized by a conventional method, and then the obtained diazo compound and a compound represented by the following formula (10) are subjected to a coupling reaction by a conventional method. The compound represented by (11) is obtained.

  By diazotizing the obtained compound represented by the above formula (11) by a conventional method, the resulting diazo compound and a compound represented by the following formula (12) are subjected to a coupling reaction by a conventional method. The azo compound of the present invention represented by the above formula (1) can be obtained.

  In addition, the compound represented by the said Formula (12) is compoundable according to the method of the said patent document 3.

Although it does not specifically limit as a suitable specific example of the azo compound represented by the said Formula (1), The compound etc. which are shown by the structural formula given to the following Tables 1-3 are mentioned.
In each table, functional groups such as sulfo group and carboxy group are described in the form of free acid for convenience. In the following formula, Ac represents an acetyl group.

  The diazotization of the compound represented by the above formula (5) is carried out by a method known per se, for example, nitrite, for example, in an inorganic acid medium at a temperature of, for example, -5 to 30 ° C, preferably 0 to 15 ° C. It is carried out using an alkali metal nitrite such as sodium nitrite. Coupling of the diazotized compound of the compound represented by the above formula (5) and the compound represented by the above formula (6) is also carried out under known conditions. It is advantageous to carry out in water or an aqueous organic medium, for example at a temperature of -5 to 30 ° C, preferably 0 to 25 ° C, and at an acidic to neutral pH value, for example pH 1-6. Since the diazotization reaction liquid is acidic and the reaction system is further acidified by the progress of the coupling reaction, the pH value is adjusted to a preferable pH condition of the reaction liquid by adding a base. Examples of the base that can be used include alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate, acetates such as sodium acetate, ammonia, and organic amines. . The compound represented by the above formula (5) and the compound represented by the above formula (6) are used in a substantially stoichiometric amount.

  The diazotization of the compound represented by the above formula (7) is carried out by a method known per se, for example, nitrite, for example, in an inorganic acid medium at a temperature of, for example, -5 to 40 ° C, preferably 5 to 30 ° C. It is carried out using an alkali metal nitrite such as sodium nitrite. Coupling of the diazotized compound of the compound represented by the above formula (7) and the compound represented by the above formula (8) is also carried out under known conditions. It is advantageous to carry out the reaction in water or an aqueous organic medium, for example at a temperature of -5 to 40 ° C, preferably 10 to 30 ° C, and at an acidic to neutral pH value, for example pH 2-7. Since the diazotization reaction liquid is acidic and the reaction system is further acidified by the progress of the coupling reaction, the pH value is adjusted to a preferable pH condition of the reaction liquid by adding a base. The same base as described above can be used. The compound represented by formula (7) and the compound represented by formula (8) are used in a substantially stoichiometric amount.

  The diazotization of the compound represented by the above formula (9) is carried out by a method known per se, for example, a nitrite such as nitrous acid in an inorganic acid medium, for example, at a temperature of -5 to 50 ° C, preferably 5 to 40 ° C. It is carried out using an alkali metal nitrite such as sodium nitrate. Coupling of the diazotized product of the compound represented by the above formula (9) and the compound represented by the above formula (10) is also carried out under conditions known per se. It is advantageous to carry out the reaction in water or an aqueous organic medium, for example at a temperature of -5 to 50 ° C, preferably 10 to 40 ° C, and at an acidic to neutral pH value, for example pH 2-7. Since the diazotization reaction liquid is acidic and the reaction system is further acidified by the progress of the coupling reaction, the pH value is adjusted to a preferable pH condition of the reaction liquid by adding a base. The same base as described above can be used. The compound represented by the above formula (9) and the compound represented by the above formula (10) are used in a substantially stoichiometric amount.

  The diazotization of the compound represented by the above formula (11) is also carried out by a method known per se, for example, a nitrite such as nitrous acid in an inorganic acid medium at a temperature of, for example, -5 to 50 ° C, preferably 10 to 40 ° C. It is carried out using an alkali metal nitrite such as sodium. Coupling of the diazotized compound of the compound represented by the above formula (11) and the compound represented by the above formula (12) is also carried out under known conditions. It is advantageous to carry out the reaction in water or an aqueous organic medium, for example at a temperature of -5 to 50 ° C, preferably 10 to 40 ° C, and at a weakly acidic to alkaline pH value. It is preferably carried out at a weakly acidic to weakly alkaline pH value, for example, pH 5 to 10, and the pH value is adjusted by adding a base. The same base as described above can be used. The compound represented by the above formula (11) and the compound represented by the above formula (12) are used in a substantially stoichiometric amount.

The salt of the azo compound represented by the above formula (1) is a salt with an inorganic or organic cation. Among them, examples of the salt with an inorganic cation include alkali metal salts, alkaline earth metal salts, and ammonium salts. Preferred inorganic salts are lithium, sodium, potassium salts, and ammonium salts. Examples of the salt with an organic cation include, but are not limited to, a salt with a quaternary ammonium ion represented by the following formula (13).
Moreover, the state which mixed the free acid of the azo compound represented by the said Formula (1), its tautomer, and those various salts may be sufficient. For example, any combination such as a mixture of sodium salt and ammonium salt, a mixture of free acid and sodium salt, a mixture of lithium salt, sodium salt, and ammonium salt may be used. Depending on the type of salt, the physical properties such as solubility may differ, and if necessary, the type of salt is selected as appropriate, or if multiple salts are included, the ratio is changed to meet the purpose. A mixture having physical properties can also be obtained.

In the above formula (13), Z ¹ , Z ² , Z ³ , and Z ⁴ are each independently selected from the group consisting of a hydrogen atom, an unsubstituted alkyl group, a hydroxyalkyl group, and a hydroxyalkoxyalkyl group. Represents a group, at least one of which is a group other than a hydrogen atom. Specific examples of the alkyl group of Z ^{1 to} Z ⁴ in the above formula (13) include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl. Specific examples of the hydroxyalkyl group include hydroxymethyl group, hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, 4-hydroxybutyl group, 3-hydroxybutyl group, 2-hydroxy group. Examples of the hydroxyalkoxyalkyl group include hydroxyethoxymethyl group, 2-hydroxyethoxyethyl group, 3-hydroxyethoxypropyl group, and 2-hydroxyethoxypropyl. Group, 4-hydroxyethoxybutyl group, 3-hydroxyethyl Kishibuchiru group, 2-hydroxyethoxy butyl group hydroxy (C1 -C4) and alkoxy (C1 -C4) alkyl group. Among these, a hydroxyethoxy (C1-C4) alkyl group is preferable. Particularly preferred are a hydrogen atom, a methyl group, a hydroxymethyl group, a hydroxyethyl group, a 3-hydroxypropyl group, a 2-hydroxypropyl group, a 4-hydroxybutyl group, a 3-hydroxybutyl group, a 2-hydroxybutyl group, and the like. Hydroxy (C1-C4) alkyl group, hydroxyethoxymethyl group, 2-hydroxyethoxyethyl group, 3-hydroxyethoxypropyl group, 2-hydroxyethoxypropyl group, 4-hydroxyethoxybutyl group, 3-hydroxyethoxybutyl group, Examples thereof include hydroxyethoxy (C1-C4) alkyl groups such as 2-hydroxyethoxybutyl group.

Specific examples of combinations of Z ¹ , Z ² , Z ³ and Z ^{4 in} the preferred compound represented by the above formula (13) are shown in Table 4 below.

As a method for synthesizing a desired salt of the azo compound represented by the above formula (1), after completion of the final step in the synthesis reaction of the compound represented by the above formula (1), a desired inorganic salt or organic salt is obtained. A method of salting out by adding a quaternary ammonium salt to the reaction solution, adding a mineral acid such as hydrochloric acid to the reaction solution and isolating the azo compound from the reaction solution in the form of a free acid, If necessary, it is washed with water, acidic water, an aqueous organic medium, etc. to remove impurities such as attached inorganic salts, and again in the aqueous medium (preferably in water) Examples thereof include a method in which an inorganic base or an organic base corresponding to the quaternary ammonium salt is added to form a salt. By these methods, the salt of the target azo compound can be obtained as a solution or a precipitated solid. The acidic water refers to water made acidic by dissolving a mineral acid such as sulfuric acid or hydrochloric acid or an organic acid such as acetic acid in water. The aqueous organic medium refers to an admixture of water and an organic substance and / or organic solvent that is miscible with water. Examples of water-miscible organic substances and organic solvents include water-soluble organic solvents described later.
Examples of inorganic salts used when the azo compound represented by the above formula (1) is used as a desired salt include halogen salts of alkali metals such as lithium chloride, sodium chloride and potassium chloride, lithium carbonate, sodium carbonate and carbonic acid. Alkali metal carbonates such as potassium, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, ammonium ion halogen salts such as ammonium chloride and ammonium bromide, ammonium hydroxide (ammonia water) And ammonium ion hydroxides. Examples of the organic cation salt include halogen salts of quaternary ammonium ions represented by the above formula (13) such as diethanolamine hydrochloride and triethanolamine hydrochloride.

  The ink composition will be described. The azo compound represented by the above formula (1) can dye a material made of cellulose by forming an aqueous composition containing the compound. Further, it is possible to dye materials having a carbonamide bond, and it can be widely used for dyeing leather, fabrics, paper, and the like. On the other hand, a typical usage of the azo compound represented by the formula (1) is an ink composition dissolved in a liquid medium, and is preferably used as an ink composition for ink jet recording.

  The reaction liquid containing the compound represented by the above formula (1), for example, the reaction liquid after the final step in the synthesis reaction of the compound represented by the above formula (1) is directly used for the production of the ink composition. be able to. However, a method of drying the reaction solution, for example, spray drying, a method of salting out by adding an inorganic salt such as sodium chloride, potassium chloride, calcium chloride, or sodium sulfate to the reaction solution, hydrochloric acid, sulfuric acid to the reaction solution The compound is isolated by a method such as acid precipitation by adding a mineral acid such as nitric acid, or a method of acid precipitation using a combination of the above salting out and acid precipitation. Compositions can also be prepared. The azo compound of the present invention is preferably used after being isolated.

  The ink composition usually contains 0.1 to 20% by mass, preferably 1 to 10% by mass, more preferably 2 to 8% by mass of an azo compound represented by the formula (1) as a pigment. Ink composition. The ink composition is prepared using water as a medium, and may contain a water-soluble organic solvent and an ink preparation agent as necessary within a range that does not impair the effects of the present invention. The water-soluble organic solvent may have a function as a dye-dissolving agent, a drying inhibitor (wetting agent), a viscosity modifier, a penetration accelerator, a surface tension modifier, an antifoaming agent, and the like. Is preferably contained. Examples of the ink preparation agent include antiseptic / antifungal agents, pH adjusters, chelating reagents, rust preventives, water-soluble ultraviolet absorbers, water-soluble polymer compounds, dye solubilizers, antioxidants, and surfactants. These additives may be mentioned. The ink composition has a water-soluble organic solvent content of 0 to 30 mass%, preferably 5 to 30 mass%, and an ink preparation agent of 0 to 15 mass%, preferably 0 to 7 mass%, based on the total mass. It may be contained. The remainder other than the above is water. The pH of the ink composition is preferably pH 5 to 11 and more preferably pH 7 to 10 in terms of improving storage stability. The surface tension of the ink composition is preferably 25 to 70 mN / m, and more preferably 25 to 60 mN / m. Furthermore, the viscosity of the ink composition is preferably 30 mPa · s or less, and more preferably 20 mPa · s or less.

In addition to the azo compound represented by the above formula (1), the ink composition may appropriately contain other toning pigments and the like for the purpose of adjusting the subtle shade of black. Even in such a case, the total mass of the pigment contained in the ink composition may be in the above range with respect to the total mass of the ink composition.
Examples of toning dyes include yellow (for example, CI Direct Yellow 34, CI Direct Yellow 58, CI Direct Yellow 86, CI Direct Yellow 132, CI Direct Yellow 161, etc. ), Orange (for example, CI Direct Orange 17, CI Direct Orange 26, CI Direct Orange 29, CI Direct Orange 39, CI Direct Orange 49, etc.), Brown, Scarlet (E.g., CI Direct Red 89), red (e.g., CI Direct Red 62, CI Direct Red 75, CI Direct Red 79, CI Direct Red 80, CI Direct Red 84, CI Direct Red 225, CI Direct Red 226), magenta (for example, CI Direct Red 227), violet, blue, navy, cyan (for example, CI Direct Blue 199, CI Acid Blue 249, etc.), green (for example, Acid Green 1) ), Black (for example, CI Acid Black 2), and other dyes having various hues.
The ink composition can be used by blending one or more kinds of these toning dyes as long as the effect obtained by the azo compound represented by the formula (1) is not impaired. Even in this case, the total amount of the coloring matter contained in the ink composition may be in the above range. The blending ratio of the azo compound represented by the above formula (1) and the toning dye is approximately 20: 1 to 1: 2, preferably 10 although it depends on the hue of the toning dye. : 1 to 1: 1. When the ink composition is used as an ink for ink jet recording, an ink containing a small amount of inorganic impurities such as chlorides and sulfates of metal cations in the azo compound represented by the above formula (1) is used. Is preferred. The standard of the content of the inorganic impurities is about 1% by mass or less with respect to the total mass of the pigment. The lower limit may be less than the detection limit of the analytical instrument, that is, 0%. In order to produce the azo compound represented by the above formula (1) with a small amount of inorganic impurities, for example, a method using a reverse osmosis membrane, a dried product or a wet cake of the azo compound represented by the above formula (1), such as methanol The suspension may be suspended and purified by stirring in a mixed solvent of alcohol, preferably (C1-C4) alcohol and water, and the precipitate may be desalted by a known method such as a method of separating the precipitate by filtration and drying.

  Specific examples of water-soluble organic solvents that can be used in the preparation of the ink composition include (C1-C4) alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, and tert-butanol, Carboxylic acid amides such as N, N-dimethylformamide and N, N-dimethylacetamide, lactams such as 2-pyrrolidone, hydroxyethyl-2-pyrrolidone, N-methyl-2-pyrrolidone and N-methylpyrrolidin-2-one; Cyclic ureas such as 1,3-dimethylimidazolidin-2-one, 1,3-dimethylhexahydropyrimido-2-one, acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one, etc. Cyclic ring such as ketone or ketoalcohol, tetrahydrofuran, dioxane Ether, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,4-butylene glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol , Dipropylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol, dithiodiglycol, mono-, oligo-, or polyalkylene glycols or thioglycols having a C2-C6 alkylene unit, trimethylolpropane, glycerin, hexane-1,2 Polyol (preferably triol) such as 1,6-triol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol (C1-C4) alkyl ethers of polyhydric alcohols such as methyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether (butyl carbitol) triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, γ-butyrolactone, dimethyl sulfoxide, etc. Can be given. These organic solvents may be used alone or in combination of two or more. The water-soluble organic solvent mentioned above contains substances that are solid at room temperature, such as trimethylolpropane, but these are water-soluble even when they are solid, and when dissolved in water Since it can be used for the same purpose as the water-soluble organic solvent, it is described in the category of the water-soluble organic solvent for the sake of convenience.

  Hereinafter, antiseptic / antifungal agents, pH adjusters, chelating reagents, rust preventives, water-soluble UV absorbers, water-soluble polymer compounds, dye dissolving agents, antioxidants, and surfactants that can be used as ink preparation agents Describe.

  Examples of the antifungal agent include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one and salts thereof. These are preferably used in the ink composition in an amount of 0.02 to 1.00% by mass.

Examples of preservatives include organic sulfur, organic nitrogen sulfur, organic halogen, haloallylsulfone, iodopropargyl, N-haloalkylthio, nitrile, pyridine, 8-oxyquinoline, benzothiazole. , Isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, brominated indanone, Examples include benzyl bromacetate and inorganic salt compounds.
Specific examples of the organic halogen compound include sodium pentachlorophenol, and specific examples of the pyridine oxide compound include sodium 2-pyridinethiol-1-oxide, and specific examples of the isothiazoline compound. For example, 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 5-chloro-2 -Methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride and the like. Specific examples of other antiseptic / antifungal agents include anhydrous sodium acetate, sodium sorbate, sodium benzoate, and the like.

  As the pH adjuster, any substance can be used as long as it can control the pH of the ink within a range of about 5 to 11 without adversely affecting the prepared ink. Specific examples thereof include, for example, alkanolamines such as diethanolamine, triethanolamine and N-methyldiethanolamine, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, ammonium hydroxide (ammonia water). And alkali metal carbonates such as lithium carbonate, sodium carbonate, sodium hydrogen carbonate and potassium carbonate, alkali metal salts of organic acids such as potassium acetate, and inorganic bases such as sodium silicate and disodium phosphate.

  Specific examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracil diacetate and the like.

  Examples of the rust preventive agent include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite, and the like.

  Examples of the water-soluble ultraviolet absorber include sulfonated benzophenone compounds, benzotriazole compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

  Examples of the water-soluble polymer compound include polyvinyl alcohol, cellulose derivatives, polyamines and polyimines.

  Examples of the dye solubilizer include ε-caprolactam, ethylene carbonate, urea and the like.

  As the antioxidant, for example, various organic and metal complex antifading agents can be used. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, and the like. .

Examples of the surfactant include known surfactants such as anionic, cationic, and nonionic surfactants.
Anionic surfactants include alkyl sulfonates, alkyl carboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurates, alkyl sulfates. Polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkylaryl sulfonate, Examples thereof include diethylsulfosuccinate, diethylhexylsylsulfosuccinate, and dioctylsulfosuccinate.

  Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

  Examples of amphoteric surfactants include lauryl dimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, imidazoline derivatives, etc. Is mentioned.

Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, and other ethers, Ester systems such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl Acetylene glycol (alcohol) type such as lu-1-hexyn-3-ol, manufactured by Nisshin Chemical Co., Ltd., trade name Surfynol 104, 105, 82, 465, Olphine STG, etc., polyglycol ether type (for example, SIGMA-ALDRICH) Manufactured by Tergitol 15-S-7) and the like.
The above ink preparation agents are used alone or in combination.

  The ink composition can be obtained by mixing and stirring the above components in an arbitrary order. If desired, the obtained ink composition may be subjected to microfiltration with a membrane filter or the like to remove impurities, and when used for ink jet recording, it is preferable to perform the filtration. The pore diameter of the filter for performing microfiltration is usually 1 μm to 0.1 μm, preferably 0.8 μm to 0.1 μm.

  The ink composition can be used in various fields, but is suitable for water-based inks for writing, water-based printing inks, information recording inks, and the like, and is particularly preferably used as ink for ink-jet recording. The ink jet recording method is preferably used.

  The ink jet recording method is a method of recording by using the ink composition of the present invention as an ink, ejecting ink droplets of the ink in accordance with a recording signal, and attaching the ink droplet to a recording material. In the ink jet recording method of the present invention, there are no particular limitations on the ink head, ink nozzles, and the like used for recording, and the ink recording method can be appropriately selected according to the purpose. This recording method is a known method, for example, a charge control method that ejects ink using electrostatic attraction, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezo element, and an electrical signal as an acoustic beam. Ink jet method that irradiates ink by changing to, and discharges ink by using the radiation pressure, thermal ink jet that heats ink to form bubbles and uses the generated pressure, so-called bubble jet (registered trademark) method , Etc. can be used.

The recording material used in the inkjet recording method is not particularly limited, and examples thereof include information transmission sheets such as paper and film, fibers and cloths (cellulose, nylon, wool, etc.), leather, and color filter base materials. Among them, an information transmission sheet is preferable.
The information transmission sheet is preferably a surface-treated sheet, specifically, a sheet, a synthetic paper, a film or other base material provided with an ink receiving layer. The ink receiving layer is formed by, for example, impregnating or coating the base material with a cationic polymer, porous white inorganic material capable of absorbing the pigment in the ink, such as porous silica, alumina sol, and special ceramics. It is provided by a method such as coating on the surface of the substrate together with a hydrophilic polymer such as pyrrolidone. The information transmission sheet provided with such an ink receiving layer is usually called ink jet dedicated paper (film), glossy paper (film) or the like. Specific examples include Canon Inc., trade name: Professional Photo Paper, Super Photo Paper or Matt Photo Paper, Seiko Epson Corporation, trade name: Photographic Paper (Glossy), PM Matte Paper, Crispier, Japan Hewlett-Packard Co. Made by company, product name Advanced Photo Paper, Premium Plus Photo Paper, Premium Glossy Film or Photo Paper, etc. are available and are available as commercial products. Of course, plain paper can also be used.

  Among the information transmission sheets, it is known that an image recorded on a sheet coated with a porous white inorganic substance has a particularly large discoloration due to ozone gas. However, since the ink composition of the present invention is excellent in ozone gas resistance, a great effect is exhibited even when ink jet recording is performed on such a recording material.

  In order to record on a recording material by the ink jet recording method, for example, a container containing the ink composition may be loaded at a predetermined position of an ink jet printer and recorded on the recording material by the above method. The ink jet recording method includes the black ink composition and, for example, known magenta, cyan, yellow, and inks of each color such as green, blue (or violet), and red (or orange) as necessary. A composition can also be used in combination. The ink composition of each color is injected into each container, and each container is loaded into a predetermined position of the ink jet printer and used for ink jet recording in the same manner as the container containing the black ink composition of the present invention.

The colored body of the present invention is
a) The azo compound according to any one of 1) to 6) or a tautomer thereof, or a salt thereof,
b) the water-based ink composition as described in 7) or 8) above, and
c) A substance colored by any one of the three methods of the ink jet recording method described in 9) above [the three of these a) to c)].
Although there is no restriction | limiting in particular about the substance to be colored, The recording material etc. which are used for said inkjet recording method are mentioned preferably.

  The azo compound of the present invention is a black pigment. This compound is easy to synthesize and inexpensive, and has a feature of low saturation. Therefore, it exhibits a more preferable hue as black, and absolute values of * a and * b as hue evaluation values are less than 12. As a result, a good black color is obtained. Moreover, since it is excellent in water solubility, the filterability with a membrane filter in the process of producing an ink composition is good. Further, the ink composition of the present invention containing the azo compound is an aqueous black ink composition, and has good storage stability without solid precipitation, physical property change, color change, etc. after long-term storage. The image recorded with the ink composition of the present invention is particularly excellent in ozone gas resistance, high printing density, excellent bronzing, low color rendering, low saturation and high quality black hue. Have Excellent fastness such as light resistance, moisture resistance and water resistance. Further, when used in combination with ink compositions containing magenta, cyan, and yellow pigments, full-color ink jet recording with excellent fastness and storage stability is possible. As described above, the ink composition containing the azo compound of the present invention can be used as an ink for ink jet recording, a writing instrument, and the like, and has excellent ejection stability. Is preferred.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by the following example. In the text, “parts” and “%” are based on mass unless otherwise specified. Each synthesis reaction, crystallization, and the like were performed under stirring unless otherwise specified. In the following formulas, acidic functional groups such as sulfo and carboxy are represented in the form of free acid. The pH value and the reaction temperature in the synthesis reaction are both measured values in the reaction system. Moreover, the maximum absorption wavelength (λmax) of the synthesized compound was measured in an aqueous solution having a pH of 7 to 8, and the measured value of the measured compound was described in Examples. The azo compounds of the present invention synthesized in the following examples all showed a solubility of 100 g / liter or more in water.

[(A) Synthesis of dye]
[Example 1]
(Process 1)
After adding 5.1 parts of aniline-2,4-disulfonic acid represented by the following formula (17) to 50 parts of water, an aqueous solution was obtained at pH 4.0 to 5.0 by adding a 25% aqueous sodium hydroxide solution. . After adding 6.3 parts of 35% hydrochloric acid, 4.2 parts of 40% aqueous sodium nitrite solution was added and reacted for about 30 minutes. The sulfamic acid 0.8 part was added here and it stirred for 5 minutes, and obtained the diazo reaction liquid. On the other hand, after adding 5.7 parts of the compound of the formula (16) obtained by the method described in International Publication No. 2012/081640 to 100 parts of water, pH 4.0 to 5.0 by adding a 25% aqueous sodium hydroxide solution. As an aqueous solution was obtained. This aqueous solution was added dropwise to the diazo reaction solution obtained above in about 5 minutes. After dropping, the reaction was continued for 3 hours while maintaining the pH at 2.0 to 4.0 by adding a 15% aqueous sodium carbonate solution, then sodium chloride was added to adjust the pH to 0.8 to 1.0 with 35% hydrochloric acid. did. The precipitated solid was collected by filtration to obtain 24.8 parts of a wet cake containing a compound represented by the following formula (18).

(Process 2)
After adding the total amount of the wet cake of the compound represented by the formula (18) obtained in Example 1 (Step 1) to 80 parts of water, pH 6.0 to 7.0 was obtained by adding a 25% aqueous sodium hydroxide solution. As an aqueous solution was obtained. After adding 5.63 parts of 35% hydrochloric acid, 3.8 parts of 40% aqueous sodium nitrite solution was added and reacted for about 30 minutes. The sulfamic acid 0.8 part was added here and it stirred for 5 minutes, and obtained the diazo reaction liquid. On the other hand, after adding 5.7 parts of the compound of the formula (16) obtained by the method described in International Publication No. 2012/081640 to 100 parts of water, pH 4.0 to 5.0 by adding a 25% aqueous sodium hydroxide solution. As an aqueous solution was obtained. This aqueous solution was added dropwise to the diazo reaction solution obtained above in about 5 minutes. After the dropwise addition, the reaction was continued for 3 hours while maintaining the pH at 2.0 to 2.5 by adding 15% aqueous sodium carbonate solution, then sodium chloride was added, and the acid was adjusted to pH 0.8 to 1.0 by adding 35% hydrochloric acid. Salted out. The precipitated solid was collected by filtration to obtain 33.2 parts of a wet cake containing a compound represented by the following formula (19).

(Process 3)
33.2 parts of a wet cake of the compound represented by the formula (19) obtained in Example 1 (Step 2) above was added to 100 parts of water and dissolved by stirring. After adding 4.7 parts of 35% hydrochloric acid, 3.2 parts of 40% aqueous sodium nitrite solution was added and stirred for about 30 minutes. 0.4 part of sulfamic acid was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid. On the other hand, after adding 5.7 parts of the compound of the formula (16) obtained by the method described in International Publication No. 2012/081640 to 100 parts of water, pH 4.0 to 5.0 by adding a 25% aqueous sodium hydroxide solution. As an aqueous solution was obtained. This aqueous solution was added dropwise to the diazo reaction solution obtained above in about 5 minutes. After the dropwise addition, the reaction was continued for 3 hours while maintaining the pH at 2.0 to 2.5 by adding 15% aqueous sodium carbonate solution, then sodium chloride was added, and the acid was adjusted to pH 0.8 to 1.0 by adding 35% hydrochloric acid. Salted out. The precipitated solid was collected by filtration to obtain 35.2 parts of a wet cake containing a compound represented by the following formula (20).

(Process 4)
To 80 parts of water, 35.2 parts of a wet cake of the compound represented by the formula (20) obtained in Example 1 (Step 3) was added and dissolved by stirring. After adding 6.3 parts of 35% hydrochloric acid, 2.3 parts of 40% aqueous sodium nitrite solution was added and stirred for about 30 minutes. 0.5 parts of sulfamic acid was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid. On the other hand, to 80 parts of water, 4.0 parts of the compound of the following formula (21) obtained by the method described in International Publication No. 2012/081640 is added, and pH 6.0 to 7 is added by adding 5% aqueous sodium hydroxide solution. Solution was obtained as 0.0. The diazo reaction liquid obtained above was dropped into this aqueous solution at 15 to 30 ° C. over about 30 minutes. At this time, a 15% aqueous sodium carbonate solution was added to maintain the pH of the reaction solution at 6.5 to 7.5, and the reaction was further continued for 2 hours while maintaining the same temperature and pH adjustment. Sodium chloride was added to the reaction solution for salting out, and the precipitated solid was separated by filtration to obtain 20.3 parts of a wet cake. The obtained wet cake was dissolved in 40 parts of water, the pH was adjusted to 7.0 to 7.5 with 35% hydrochloric acid, 400 parts of methanol was added, and the precipitated solid was collected by filtration. The obtained wet cake was again dissolved in 40 parts of water, and then 300 parts of methanol was added. The precipitated solid was separated by filtration and dried to obtain a compound represented by the following formula (22) of the present invention as a black powder as 10.3 parts sodium salt.
λmax: 574 nm.

[Example 2]
(Process 1)
After adding 19.5 parts of naphthalene-1,3,7-sulfonic acid represented by the following formula (27) to 50 parts of water, the aqueous solution was adjusted to pH 4.0 to 5.0 by adding a 25% aqueous sodium hydroxide solution. Obtained. After adding 18.3 parts of 35% hydrochloric acid, 10.5 parts of 40% aqueous sodium nitrite solution was added and allowed to react for about 30 minutes. To this, 1.5 parts of sulfamic acid was added and stirred for 5 minutes to obtain a diazo reaction liquid. On the other hand, 16.7 parts of the compound of the formula (16) obtained by the method described in International Publication No. 2012/081640 is added to 50 parts of water, and the pH is adjusted to 4.0 to 5. by adding a 25% aqueous sodium hydroxide solution. An aqueous solution was obtained as zero. This aqueous solution was added dropwise to the diazo reaction solution obtained above over about 5 minutes. After the dropwise addition, the mixture was reacted for 3 hours while maintaining the pH at 4.0 to 6.0 by adding a 15% aqueous sodium carbonate solution, and then sodium chloride was added. The precipitated solid was collected by filtration to obtain 163 parts of a wet cake containing a compound represented by the following formula (28).

(Process 2)
After adding the total amount of the wet cake of the compound represented by the formula (28) obtained in Example 2 (Step 1) to 150 parts of water, pH 6.0 to 7.0 was added by adding a 25% aqueous sodium hydroxide solution. As an aqueous solution was obtained. After adding 16.5 parts of 35% hydrochloric acid, 10.6 parts of 40% aqueous sodium nitrite solution was added and allowed to react for about 30 minutes. 7.5 parts of sulfamic acid was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid. On the other hand, 16.7 parts of the compound of the above formula (16) obtained by the method described in International Publication No. 2012/081640 is added to 100 parts of water, and pH 4.0-5. An aqueous solution was obtained as zero. This aqueous solution was added dropwise to the diazo reaction solution obtained above over about 5 minutes. After the dropwise addition, the mixture was reacted for 3 hours while maintaining the pH at 4.0 to 6.0 by adding a 15% aqueous sodium carbonate solution, and then sodium chloride was added. The precipitated solid was collected by filtration to obtain 163 parts of a wet cake containing a compound represented by the following formula (29).

(Process 3)
To 100 parts of water, 76.0 parts of a wet cake of the compound represented by the formula (29) obtained in Example 2 (Step 2) was added and dissolved by stirring. After adding 7.8 parts of 35% hydrochloric acid, 2.8 parts of 40% aqueous sodium nitrite solution was added and stirred for about 30 minutes. The sulfamic acid 0.8 part was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid. On the other hand, 4.9 parts of the compound of the above formula (16) obtained by the method described in International Publication No. 2012/081640 is added to 80 parts of water, and pH 4.0-5. An aqueous solution was obtained as zero. This aqueous solution was added dropwise to the diazo reaction solution obtained above over about 5 minutes. After the dropwise addition, the reaction was allowed to proceed for 3 hours while maintaining the pH at 4.0 to 6.0 by adding a 15% aqueous sodium carbonate solution. After the pH was adjusted to 7.0 to 7.5 by adding a 25% aqueous sodium hydroxide solution, sodium chloride was added. The precipitated solid was collected by filtration to obtain 53 parts of a wet cake containing a compound represented by the following formula (30).

(Process 4)
In 80 parts of water, 53 parts of a wet cake of the compound represented by the formula (30) obtained in Example 2 (Step 3) was added and dissolved by stirring. After adding 6.3 parts of 35% hydrochloric acid, 2.3 parts of 40% aqueous sodium nitrite solution was added and stirred for about 30 minutes. 0.5 parts of sulfamic acid was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid. On the other hand, 4.0 parts of the compound represented by the formula (23) obtained in Example 1 (step) above was added to 80 parts of water, and a pH of 6.0 to 7. An aqueous solution was obtained as zero. The diazo reaction liquid obtained above was dropped into this aqueous solution at 15 to 30 ° C. over about 30 minutes. At this time, a 15% aqueous sodium carbonate solution was added to maintain the pH of the reaction solution at 6.5 to 7.5, and the reaction was further continued for 2 hours while maintaining the same temperature and pH adjustment. Sodium chloride was added to the reaction solution for salting out, and the precipitated solid was separated by filtration to obtain 32.4 parts of a wet cake. The obtained wet cake was dissolved in 40 parts of water, the pH was adjusted to 7.0 to 7.5 with 35% hydrochloric acid, 400 parts of isopropanol was added, and the precipitated solid was collected by filtration. The obtained wet cake was again dissolved in 40 parts of water, and then 300 parts of isopropanol was added. The precipitated solid was separated by filtration and dried to obtain a compound represented by the following formula (31) of the present invention as a black powder as 13.5 parts sodium salt. [lambda] max: 586.5 nm.

[(B) Preparation of ink]
Using the azo compounds [Formulas (22) and (31)] of the present invention obtained in Examples 1 and 2 as dyes, the compositions shown in Table 5 below are mixed to form a solution. An ink composition was obtained. The obtained ink composition was filtered through a 0.45 μm membrane filter to remove impurities, and a test ink was prepared. The pH of this test ink was in the range of 8.0 to 9.5. In Table 7 below, “surfactant” used was the trade name Surfinol ^RTM 104PG50 manufactured by Nissin Chemical Co., Ltd. Preparation of an ink using the compound obtained in Example 1 is referred to as Example 3. In addition, each test ink was prepared in the same manner as in Example 3 except that the dye obtained in Example 2 was used instead of the dye obtained in Example 1. This ink is referred to as Example 4.

[Comparative Example 1]
A comparative ink was prepared in the same manner as in Example 3 except that the dye described in International Publication No. 2012/081640 (Example 3) was used instead of the compound of the present invention obtained in Example 1. This ink preparation is referred to as Comparative Example 1. The structural formula of the compound used in Comparative Example 1 is shown in the following formula (32).

[(C) Inkjet recording]
Each ink prepared in Examples 3 to 4 and Comparative Example 1 was subjected to ink jet recording on the following glossy paper using an ink jet printer (manufactured by Canon Inc., trade name: PIXUS ^RTM ip 7230). At the time of recording, an image pattern was prepared so that six gradation levels of 100%, 85%, 70%, 55%, 40%, and 25% density were obtained, and a halftone recorded matter was obtained. Using the obtained recorded matter as a test piece, the following test was conducted.

  Glossy paper: Seiko Epson Corporation, trade name: PM photo paper

[(D) Color measurement of recorded image]
Various tests and the evaluation thereof were performed by measuring the color of a test piece using a colorimeter manufactured by X-rite and a trade name of SpectroEye. Colorimetry was performed under the conditions of DIN NB, viewing angle of 2 degrees, and light source D65 as density standards.

[(D) Hue evaluation test]
The hue (a * b *) of the test piece obtained in [(C) Inkjet recording] was measured using the color measurement system. The lower the a * b *, the lower the saturation and the better the black dye. The results are shown in Table 6. The evaluation criteria are as follows.
Absolute value of * a, * b is 10 or less at any concentration
The absolute value of * a and * b exceeds 10 and is less than 12 at any concentration.
Absolute value of * a, * b is 12 or more at any concentration

  From the above, it can be seen that the water-soluble azo compound of the present invention and the ink composition of the present invention containing the compound have a better hue of the printed matter than the conventional dyes. Moreover, the test piece obtained using the ink of the present example showed good ozone resistance.

  The azo compound of the present invention and the ink composition containing the azo compound are suitably used for black ink for various recordings such as writing utensils, particularly ink jet recording.

Claims (10)

An azo compound represented by the following formula (1), a tautomer thereof, or a salt thereof.

[In Formula (1),
R ₁ represents a (C1-C4) alkyl group or a (C1-C4) alkyl group substituted with a carboxy group,
R ₂ represents a cyano group,
R ₃ and R ₄ each independently represents a hydrogen atom, a (C1-C4) alkoxyl group, or a sulfo group,
R ₅ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ₆ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ₇ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ₈ represents a (C1 to C4) alkylcarbonylamino group,
R ₉ is a (C1-C4) alkylcarbonylamino group,
R ₁₀ represents a (C1-C4) alkylcarbonylamino group,
R _{11 to} R ₁₃ are each independently a hydrogen atom, a sulfo group, a carboxy group, a hydroxy group, or a nitro group. In addition, when there is no ring represented by a broken line, a benzene ring, when there is a ring represented by a broken line, a naphthalene ring, and when it is a naphthalene ring, the substituents R _{11 to} R ₁₃ are each a naphthalene ring. Can be substituted at any position. ] In the above formula (1),
R ₁ represents a (C1-C4) alkyl group or a (C1-C4) alkyl group substituted with a carboxy group,
R ₂ represents a cyano group,
R ₃ and R ₄ each independently represents a hydrogen atom, a (C1-C4) alkoxyl group, or a sulfo group,
R ₅ represents a sulfo (C1-C4) alkylthio group,
R ₆ represents a sulfo (C1-C4) alkylthio group, R ₇ represents a sulfo (C1-C4) alkylthio group,
R ₈ represents a (C1 to C4) alkylcarbonylamino group,
R ₉ is a (C1-C4) alkylcarbonylamino group,
R ₁₀ represents a (C1-C4) alkylcarbonylamino group,
The azo compound according to claim 1, or a tautomer thereof, or a salt thereof, wherein R _{11 to} R ₁₃ are each independently a hydrogen atom, a sulfo group, a carboxy group, a hydroxy group, or a nitro group. In the above formula (1),
R ₁ is a methyl group,
R ₂ is a cyano group,
R ₃ is a methoxy group or a hydrogen atom,
R ₄ is a sulfo group,
R ₅ is a sulfo (C1-C4) alkylthio group,
R ₆ is a sulfo (C1-C4) alkylthio group,
R ₇ is a sulfo (C1-C4) alkylthio group,
R ₈ is an acetylamino group,
R ₉ is an acetylamino group,
R ₁₀ is an acetylamino group,
R < ₁₁ > -R < ₁₃ > is a hydrogen atom, a sulfo group, a carboxy group, a hydroxy group, or a nitro group each independently, The azo compound or its tautomer, or its salt of Claim 1 or 2 .   An aqueous ink composition comprising at least one kind of the azo compound according to any one of claims 1 to 3 or a tautomer thereof, or a salt thereof as a coloring matter.   The water-based ink composition according to claim 4, further comprising a water-soluble organic solvent.   An ink jet recording method in which recording is performed on a recording material by using the water-based ink composition according to claim 4 or 5 as ink, and discharging ink droplets of the ink according to a recording signal.   The inkjet recording method according to claim 6, wherein the recording material is an information transmission sheet.   8. The ink jet recording method according to claim 7, wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance.   An ink jet printer loaded with a container containing the water-based ink composition according to claim 4. a) the azo compound according to any one of claims 1 to 3 or a tautomer thereof, or a salt thereof;
b) The water-based ink composition according to claim 4 or 5, or
c) A colored body colored by any one of the three methods of the ink jet recording method according to claim 6.